Sure you can use one, but whether you should would depend on what it's main purpose will be. IMO, it will not make a good biological filter, but will do fine for some waterflow, chemical and some mechanical filtration.

I use 2 Tetratec 500's on my 125 galSW tank now. Other than them being a bit noisy, they work fine. Just rotate the filters like they recommend. I change mine by moving the back ones to the front and placing the new ones in the back. I also do not change "both" of the units at the same time. They get changed a week apart.

I used one in my 20 gallon tank and it works great. Like reefrunner said they are good for flow, mechanical and chemical filtration. The tidal flow thing can be a bit touchy but when it works its almost like having a wavemaker. You can even get the heater for it and keep the inside of the tank neater. The only problem I had with it was sand ruined the impeller and I had to replace it(the impeller).